Parthenium hysterophorus is an extremely invasive plant species widely spread across various regions, including India. It is recognized for emitting airborne allergens, which have the potential to induce allergic responses in susceptible individuals. The objective of this study was to examine the prevalence of allergies triggered by parthenium among individuals with allergies living in Chapra town, Bihar, India. The research spanned a two-year period from 2018 to 2020, and the RotoRod Sampler method was utilized to gather data on environmental parameters. Daily information on environmental conditions was obtained from the Bihar Meteorological Department, while data on pollen allergy patients were collected from Sadar Hospital in Chapra. The investigation reports of patients belonging to different age groups were compiled for analysis. The findings indicated that the high concentration of parthenium pollen in the air had significant implications for pollinosis. The spring season is associated with the highest recorded levels of pollen, and there is a clear connection between the release of pollen and the number of individuals suffering from allergies. This correlation affects both local residents and people visiting the area during the peak period of the year. It is recommended that authorities and forest departments exercise caution when selecting invasive species for plantation.